Estimation of Urinary Lead and Urinary δ-Aminolevulinic Acid as an Index of Lead Exposure in Urban and Rural Residents of West Bengal, India.

Abstract

Background: Chronic exposure to low-level environmental lead (Pb) causes several health effects in humans. Its biomonitoring by non-invasive biomarkers is imperative to identify Pb exposure in the occupationally unexposed general public.

Objective: To quantify urinary lead (U-Pb) and urinary δ-Aminolevulinic acid (ALA) in the general population of West Bengal, India, and identify the impact of routine life activities (smoking habit, traveling, and cooking activities) and sociodemographic factors on U-Pb and U-ALA levels.

Method: Urine samples (N = 258) were obtained from urban and rural area residents from November 2021 to February 2022. U-Pb and U-ALA were quantified by atomic absorption (283 nm) and UV-spectrometer (553 nm). A structured questionnaire was used for data collection.

Results: About 8% of rural residents, 15% of urban residential area residents, and 35% of urban commercial area residents had U-ALA levels > 5 mg/L permissible limit. Low-income-group (LIG) individuals had two times higher ALA than the middle-income group. ALA was significantly (P < 0.05) higher in smoker traveler males, traveler females, and females who had passive exposure to tobacco smoke. U-Pb was within permissible limits in total study individuals.

Conclusion: Pb exposure was higher in urban than rural residents; furthermore, urban commercial residents had Pb exposure higher than urban residential residents. Results are evident that vehicular emissions and tobacco smoke were potential contributors to environmental Pb exposure among study participants. The present work provides data on Pb body burden among the residents of West Bengal that might be useful for policymakers and in pollution abatement strategies too.